I don't get how to reference two classes(Parent and Child)

Question

class First {
    int var = 1;
    
    int method() {
        return var;
    }
}

class Second extends First {
    int var = 2;
    
    int method() {
        return var;
    }
} 

public class Test {
    public static void main(String[] args) {
        First s = new Second();
        System.out.println(s.var);
        System.out.println(s.method());
    }
}